eg:
select str_to_date('2014-12-21 12%3A34%3A56', '%Y-%m-%d %H%%3A%i%%3A%s');
select unix_timestamp('2007-11-30 10:30%3A19', '%Y-%m-%d %H:%i%%3A%s');
This also enable us to extract column fields from HDFS file path with contains '%'.
Format of some docs are incorrect for building the doc website.
* fix a bug that `gensrc` dir can not be built with -j.
* fix ut bug of CreateFunctionTest
Fixes#2771
Main changes in this CL
* RoaringBitmap is renamed to BitmapValue and moved into bitmap_value.h
* leveraging Roaring64Map to support unsigned BIGINT for BITMAP type
* introduces two new format (SINGLE64 and BITMAP64) for BITMAP type
So far we have three storage format for BITMAP type
```
EMPTY := TypeCode(0x00)
SINGLE32 := TypeCode(0x01), UInt32LittleEndian
BITMAP32 := TypeCode(0x02), RoaringBitmap(defined by https://github.com/RoaringBitmap/RoaringFormatSpec/)
```
In order to support BIGINT element and keep backward compatibility, introduce two new format
```
SINGLE64 := TypeCode(0x03), UInt64LittleEndian
BITMAP64 := TypeCode(0x04), CustomRoaringBitmap64
```
Please note that SINGLE64/BITMAP64 doesn't replace SINGLE32/BITMAP32. Doris will choose the smaller (in terms of space) type automatically during serializing. For example, BITMAP32 is preferred over BITMAP64 when the maximum element is <= UINT32_MAX. This will also make BE rollback possible as long as user didn't write element larger than UINT32_MAX into bitmap column.
Another important design decision is that we fork and maintain our own version of Roaring64Map instead of using the one in "roaring/roaring64map.hh". The reasons are
1. RoaringBitmap doesn't define a standard for the binary format of 64-bits bitmap. As a result, different implementations of Roaring64Map use different format. For example the [C++ version](https://github.com/RoaringBitmap/CRoaring/blob/v0.2.60/cpp/roaring64map.hh#L545) is different from the [Java version](35104c564e/src/main/java/org/roaringbitmap/longlong/Roaring64NavigableMap.java (L1097)). Even for CRoaring, the format may change in future releases. However Doris require the serialized format to be stable across versions. Fork is a safe way to achieve this.
2. We may want to make some code changes to Roaring64Map according to our needs. For example, in order to use the BITMAP32 format when the maximum element can be represented in 32 bits, we may want to access the private member of Roaring64Map. Another example is we want to further customize and optimize the format for BITMAP64 case, such as using vint64 instead of uint64 for map size.
This CL changes:
1. add function bitmap_to_string and bitmap_from_string, which will
convert a bitmap to/from string which contains all bit in bitmap
2. add function murmur_hash3_32, which will compute murmur hash for
input strings
3. make the function cast float to string the same with user result
logic
This CL make bitmap_count, bitmap_union, and bitmap_union_count accept any expression whose return type is bitmap as input so that we can support flexible bitmap expression such as bitmap_count(bitmap_and(to_bitmap(1), to_bitmap(2))).
This CL also create separate documentation for each bitmap UDF to conform with other functions.
Add a new type: Object. Currently, it's mainly for complex aggregate metrics(HLL , Bitmap).
The Object type has the following constraints：
1 Object type could not as key column type
2 Object type doesn't support all indices (BloomFilter, short key, zone map, invert index)
3 Object type doesn't support filter and group by
In the implementation：
The Object type reuse the StringValue and StringVal, because in storage engine, the Object type is binary, it has a pointer and length.
